/* -------------------------------------------------------------
   Carta Case Study · Loop Agency / Framer Editorial Design System
   Architecture: High-Craft Swiss / Neo-Grotesque Brutalism
-------------------------------------------------------------- */

:root {
  color-scheme: dark;

  /* Obsidian Dark Palette */
  --bg: #0a0a0a;
  --bg-subtle: #141414;
  --surface: #1a1a1a;
  --surface-hover: #262626;
  --text: #ffffff;
  --text-muted: #888888;
  --text-dim: #666666;
  --line: #1f1f1f;
  --line-strong: #383838;
  --accent: #d4e0c4;
  --accent-ink: #0a0a0a;

  /* Warm Tactile Media Stage */
  --media-bg: #e8dfcc;
  --media-surface: #ded4bf;
  --media-ink: #2b231b;
  --media-line: rgba(43, 35, 27, 0.12);
  --media-border: rgba(43, 35, 27, 0.08);

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Monaco, Consolas, monospace;

  --header-height: 56px;
  --gutter: clamp(1.25rem, 3.5vw, 3.5rem);
  --shell-max: 1380px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-screen: 18px;

  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --duration: 200ms;
}

html[data-theme="light"] {
  color-scheme: light;
  --bg: #ffffff;
  --bg-subtle: #f5f5f5;
  --surface: #ebebeb;
  --surface-hover: #dedede;
  --text: #000000;
  --text-muted: #666666;
  --text-dim: #999999;
  --line: #e5e5e5;
  --line-strong: #cccccc;
  --accent: #384d28;
  --accent-ink: #ffffff;
  --media-bg: #dfd4be;
  --media-surface: #d4c8b0;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 24px);
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding-top: var(--header-height);
  transition: background-color var(--duration) var(--ease), color var(--duration) var(--ease);
}

button {
  font-family: inherit;
  line-height: 1.4;
}

/* -------------------------------------------------------------
   Skip Link (Accessible off-screen)
-------------------------------------------------------------- */
.skip-link {
  position: fixed;
  top: 12px;
  left: 16px;
  z-index: 999;
  padding: 8px 16px;
  background: var(--text);
  color: var(--bg);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-radius: var(--radius-sm);
  transform: translateY(-200%);
  transition: transform var(--duration) var(--ease);
  text-decoration: none;
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--accent);
}

/* -------------------------------------------------------------
   Layout Shell
-------------------------------------------------------------- */
.shell {
  width: min(var(--shell-max), calc(100% - (var(--gutter) * 2)));
  margin-inline: auto;
}

.arrow {
  display: inline-block;
  transition: transform var(--duration) var(--ease);
}

@media (hover: hover) and (pointer: fine) {
  a:hover .arrow,
  button:hover .arrow {
    transform: translate(2px, -2px);
  }

  .back-top-link:hover .arrow {
    transform: translateY(-2px);
  }
}

/* -------------------------------------------------------------
   Global Fixed Header (Loop Agency Style)
-------------------------------------------------------------- */
.global-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  transition: background-color var(--duration) var(--ease), border-color var(--duration) var(--ease);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  padding-inline: var(--gutter);
}

.header-logo {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
  text-decoration: none;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-item {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}

.nav-item:hover,
.nav-item.is-active {
  color: var(--text);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}

.theme-switcher {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.theme-btn {
  background: transparent;
  border: 0;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  transition: color var(--duration) var(--ease);
}

.theme-btn:hover {
  color: var(--text);
}

html[data-theme="dark"] [data-theme-set="dark"],
html[data-theme="light"] [data-theme-set="light"] {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.theme-divider {
  color: var(--line-strong);
}

.mobile-menu-trigger {
  display: none;
  background: transparent;
  border: 0;
  color: var(--text);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  padding: 6px;
}

.mobile-menu-trigger .menu-label-close {
  display: none;
}

.mobile-menu-trigger[aria-expanded="true"] .menu-label-open {
  display: none;
}

.mobile-menu-trigger[aria-expanded="true"] .menu-label-close {
  display: inline;
}

/* -------------------------------------------------------------
   Hero Section (Loop Agency Style)
-------------------------------------------------------------- */
.section-hero {
  padding-top: clamp(3.5rem, 6vw, 6rem);
  padding-bottom: clamp(3rem, 5vw, 5rem);
}

.hero-meta-strip {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.meta-dot {
  color: var(--line-strong);
}

.hero-display-title {
  font-size: clamp(3.8rem, 11vw, 10rem);
  font-weight: 700;
  line-height: 0.88;
  letter-spacing: -0.04em;
  text-transform: uppercase;
  color: var(--text);
  margin-bottom: 28px;
}

.hero-thesis {
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  line-height: 1.45;
  color: var(--text);
  max-width: 820px;
  font-weight: 450;
  letter-spacing: -0.02em;
}

/* -------------------------------------------------------------
   Two-Column Asymmetric Case Content
-------------------------------------------------------------- */
.section-case {
  border-top: 1px solid var(--line);
  padding-top: clamp(3rem, 5vw, 5rem);
  padding-bottom: clamp(4rem, 7vw, 7rem);
}

.case-layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: clamp(3rem, 6vw, 6rem);
  align-items: start;
}

/* Left / Sticky Track */
.case-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 32px);
}

.sidebar-sticky-box {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.sidebar-callout {
  font-size: 13px;
  font-weight: 600;
  line-height: 1.6;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.sidebar-metadata {
  display: flex;
  flex-direction: column;
}

.meta-row {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-block: 14px;
  border-bottom: 1px solid var(--line);
}

.meta-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.meta-value {
  font-size: 14px;
  font-weight: 550;
  color: var(--text);
}

.sidebar-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 1px solid transparent;
  transition: background-color var(--duration) var(--ease),
              border-color var(--duration) var(--ease),
              color var(--duration) var(--ease);
}

.action-primary {
  background: var(--text);
  color: var(--bg);
  border-color: var(--text);
}

.action-primary:hover {
  background: var(--text-muted);
  border-color: var(--text-muted);
  color: var(--bg);
}

.action-secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--line-strong);
}

.action-secondary:hover {
  background: var(--bg-subtle);
  border-color: var(--text);
}

.action-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  padding: 6px 0;
  transition: color var(--duration) var(--ease);
}

.action-link:hover {
  color: var(--text);
}

/* Right / Scroll Track */
.case-content {
  display: flex;
  flex-direction: column;
  gap: clamp(3.5rem, 6vw, 6rem);
}

.media-container {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.media-canvas {
  background: var(--media-bg);
  color: var(--media-ink);
  border-radius: var(--radius-lg);
  padding: clamp(2.5rem, 5vw, 4.5rem);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--media-line);
}

.case-image {
  display: block;
  width: 100%;
  max-width: 320px;
  height: auto;
  border-radius: var(--radius-screen);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.2);
  border: 1px solid var(--media-border);
}

.media-caption {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-inline: 4px;
}

.caption-num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-dim);
}

.caption-text {
  font-size: 13px;
  color: var(--text-muted);
}

/* Narrative Blocks */
.narrative-section {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: clamp(2rem, 4vw, 3.5rem);
  padding-block: 8px;
}

.narrative-item {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.narrative-title {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text);
}

.narrative-body {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-muted);
}

.narrative-body code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  padding: 2px 5px;
  border-radius: 4px;
  background: var(--bg-subtle);
  border: 1px solid var(--line);
  color: var(--text);
}

/* Two-Column Showcase Split */
.media-grid-two {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.media-grid-item {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.media-canvas-compact {
  padding: clamp(1.5rem, 3vw, 2.5rem);
  min-height: 360px;
}

.case-image-compact {
  display: block;
  width: 100%;
  max-width: 220px;
  height: auto;
  border-radius: var(--radius-screen);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.18);
  border: 1px solid var(--media-border);
}

/* -------------------------------------------------------------
   Technical Architecture Deep Dive (Ruled Rows)
-------------------------------------------------------------- */
.section-engineering {
  border-top: 1px solid var(--line);
  padding-block: clamp(4rem, 7vw, 7rem);
}

.section-header-strip {
  margin-bottom: clamp(2.5rem, 4vw, 4rem);
}

.meta-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 8px;
}

.section-headline {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  color: var(--text);
}

.engineering-rows {
  display: flex;
  flex-direction: column;
}

.eng-row {
  display: grid;
  grid-template-columns: 200px 320px 1fr;
  gap: clamp(1.5rem, 3vw, 3rem);
  padding-block: clamp(2rem, 3.5vw, 3rem);
  border-top: 1px solid var(--line);
  align-items: baseline;
}

.eng-meta {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.eng-num {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--text-dim);
}

.eng-category {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.eng-title h3 {
  font-size: 18px;
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.02em;
  color: var(--text);
}

.eng-description {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.eng-description p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-muted);
}

/* -------------------------------------------------------------
   About Section
-------------------------------------------------------------- */
.section-about {
  border-top: 1px solid var(--line);
  padding-block: clamp(4rem, 7vw, 7rem);
}

.about-grid {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: clamp(3rem, 6vw, 6rem);
  align-items: start;
}

.about-facts {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 20px;
}

.fact-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.fact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.fact-val {
  font-size: 14px;
  font-weight: 550;
  color: var(--text);
}

.about-right {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.about-lead {
  font-size: clamp(1.5rem, 2.5vw, 2.2rem);
  font-weight: 550;
  line-height: 1.3;
  letter-spacing: -0.03em;
  color: var(--text);
}

.about-prose {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 680px;
}

.about-prose p {
  font-size: 15.5px;
  line-height: 1.7;
  color: var(--text-muted);
}

.about-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 8px;
  flex-wrap: wrap;
}

/* -------------------------------------------------------------
   Contact Section
-------------------------------------------------------------- */
.section-contact {
  border-top: 1px solid var(--line);
  padding-block: clamp(4rem, 7vw, 7rem);
}

.contact-headline {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  text-transform: uppercase;
  color: var(--text);
  margin-top: 8px;
}

.contact-card {
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-top: 24px;
}

.contact-email-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.2em;
  font-size: clamp(1.8rem, 5.5vw, 4.5rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  text-transform: uppercase;
  color: var(--text);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}

.contact-email-link:hover {
  color: var(--accent);
}

.contact-actions {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.copy-btn {
  min-width: 140px;
}

.copy-btn[data-copied="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}

.contact-location {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

/* -------------------------------------------------------------
   Global Footer
-------------------------------------------------------------- */
.global-footer {
  border-top: 1px solid var(--line);
  padding-block: 36px;
}

.footer-grid {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-title {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text);
  display: block;
}

.footer-sub {
  font-size: 13px;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  align-items: center;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}

.footer-links a:hover {
  color: var(--text);
}

/* -------------------------------------------------------------
   Toast Notification
-------------------------------------------------------------- */
.toast {
  position: fixed;
  right: max(16px, env(safe-area-inset-right));
  bottom: max(16px, env(safe-area-inset-bottom));
  z-index: 1000;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  background: var(--text);
  color: var(--bg);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0;
  transform: translateY(8px);
  pointer-events: none;
  transition: opacity 160ms var(--ease), transform 160ms var(--ease);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.toast.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* -------------------------------------------------------------
   Scroll Trigger Viewport Animation
-------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 350ms var(--ease), transform 350ms var(--ease);
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

/* -------------------------------------------------------------
   Responsive Breakpoints
-------------------------------------------------------------- */
@media (max-width: 1024px) {
  .case-layout {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .case-sidebar {
    position: static;
  }

  .eng-row {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .header-nav {
    display: none;
  }

  .mobile-menu-trigger {
    display: inline-block;
  }

  .header-nav.is-open {
    display: flex;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg);
    flex-direction: column;
    align-items: flex-start;
    padding: 32px var(--gutter);
    gap: 24px;
    z-index: 49;
    border-bottom: 1px solid var(--line);
  }

  .header-nav.is-open .nav-item {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
  }

  .narrative-section {
    grid-template-columns: 1fr;
  }

  .media-grid-two {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}